Can Itunes stream multi-room Audio?

I'm looking for a multi-room audio solution...

Basically I have a new house with three main living areas, a "family/kitchen/dining" room, a "home theatre" room, an upstairs "living room"

I have a windows server with a lot of media on (iTunes layout music folders, managed by iTunes on a windows PC) - also the server uploads changes in this folder to google play music, so that android devices (and chromecasts) have access to my collection via this method.

Presently my home theatre room has a chromecast plugged into an onkyo 616 amp, which has three zone output (but I have no way to route zones 2&3 ouf of the room due to insufficient cabling)...

At the moment if I want to listen to music I use my android mobile and google play music to stream out to the chromecast, and that gives me music in one room. Obviously I could equip a chromecast to each room and listen in one room (only) at a time.

What I'd like is to be able to stream music to any locaton / or all at the same time, like with Sonos - but as I have a few amps and plenty of speakers already I do NOT want to buy more speakers... so sonos / LG / Samsung multiroom solutions just don't cut it as they require a complete rethink..

What I'm wondering is can I use iTunes on the PC along with "airplay" features to stream to several locations? I have wifi AC/n/G throughout the house and wired gigabit in most main locations. the apple airport express looks like it has the connectivity to put one on each amp in the house... and if I could get them to work in sync with each other it looks like it might do what I want?

I have one ipad mini in the house, but the phones and other tablets are android and PC's / server

also been looking at the "beep" device.